German laid-open document DE 10 2004 014 773 Al discloses a drive device for a fluorine transport vehicle. The fluorine transport vehicle has a bogy that can rotate around a vertical axis and two drive wheels that are mounted on the bogy parallel and mirror-symmetrically to the vertical axis. There is a means for creating a differential effect, which is arranged between the two drive wheels. According to an embodiment for creating a differential effect between the two drive wheels, there is an electric twin-rotor engine having two rotors and a shared stator. Each rotor is coupled directly or indirectly to an adjacent drive wheel.
International patent application WO 2009/082496 Al discloses a device for transporting buildings. Here, the building to be transported rests on a support structure that, in turn, comprises four movable systems, each having at least two wheels. Each of the wheels of a movable system is associated with a motor that drives that particular wheel. A control system allows the operator to control the transport system. For this purpose, the individual motors on the movable system are actuated accordingly so that then entire transport system can be moved in the intended direction or to the intended position.
Japanese patent application JP 2004-090903 also describes a movable system comprising at least two wheels that are arranged on an axle. By the same token, the movable system can be rotated around an axis that is perpendicular to the wheel axle. An individual drive is associated with each wheel of the movable system. The movable system can be steered and controlled appropriately by suitably controlling the individual drives of the wheels.
Japanese patent application JP 55-039846 likewise discloses a transport system that is equipped with several movable systems. The movable systems can be controlled in such a way as to ensure that the transport system can move around corners of a building or of a warehouse. Each movable system of the transport system comprises two individual wheels that are each equipped with their own drives. Therefore, the transport system can be moved around the corners in a controlled manner by suitably controlling the drives of the wheels of each movable system.
U.S. Pat. No. 3,827,517 likewise discloses a movable system comprising two wheels that are arranged in a yoke. Each wheel here is associated with its own motor. The motor is driven hydrostatically.
Japanese patent application JP 2008-213570 likewise describes a movable system comprising two wheels that are arranged on a shared wheel axle. Furthermore, there is an axis that is perpendicular to the wheel axle and to the plane of movement of the movable system. The movable system can be rotated around this axis. Each wheel of the movable system is associated with a drive system. The drive systems for each wheel are configured identically.